Question

assuming ideal behavior, find the freezing point of a solution made by dissolving 13.2g of ammonium phosphate in 45.0 g of water?

Answer 1

Answer:-

The answer is given in the image,

Mass of ammonium phosphate = 13.2 g massing water (solvent) = 4.5 g Molarity m = mole times 1000/volume (g) Molar mass of Ammonium phosphate = 149.0879/mol mole of ammonium phosphate = mass/molar mass = 13.2/149.087 = 0.0885 mol molarity (m) = 0.0885 times 1000/45 = 1.967 m Freezing point depression constant As water k_f = 1.86 c /m then Delta t = k_f m Delta t = 1.86 times 1.967 Delta t = 3.66 degree C Freezing point of solution = 0 - 3.66 degree C = -3.66 degree C